As shown in the data presented in the Kiviat plot,
the three most important factors (the highest scores)
were battery recharge time (3.48222), environmental
pollution (3.43175), and battery cost (3.45469)
(shown by green circles). Therefore, it suggested that
these three factors, individually or in combination,
would be very important in determining the usage and
adoption of EVs. However, a fourth factor, energy
efficiency (3.34245), also appears to be quite
important as its score is not too far behind the top
three (shown by a yellow circle).
Also shown in the data presented in the Kiviat
plot, the two least important factors (the lowest
scores) were brake fade (1.49958) and complex
transmissions (1.90462).
Based on the analysis of the results obtained, the
top three factors spanned all the three broad
categories identified before, namely sustainability
and environment, performance and efficiency, and
design and manufacture. Therefore, investment of
resources for usage and adoption of EVs should occur
in all these three categories, with special emphasis on
the top three factors.
Battery recharge time was the most important
factor. Therefore, investment has to be made to
construct numerous battery recharge stations
available to the public. Additionally, there has to be
technology investment for reducing the battery
charge time. The next important factor was the
concern for the environment. There has to be more
education on environmental friendliness of EVs. A
research by an organization EVConnect (Portillo,
2017) showed that this is already an important factor
since many millennials are already environmentally
conscious in that “more than 55% of EV buyers are
millennials.” The third factor was battery cost, and so,
EV manufacturers need to invest on lowering the cost
of batteries. In fact, Robert Bright reported in the
Huffington Post (Bright, 2019) that “battery costs
have reduced by 65% since 2010,” thus confirming
the importance of this factor and bringing it to the top
with regard to adoption of EVs.
Thus, it was seen that this study also confirmed
some of the prevailing ideas on the importance of
factors mentioned in both specialized and popular
media. Therefore, investment in all these initiatives
will promote the usage and adoption of electric
vehicles.
6 CONCLUSIONS
This paper has highlighted the use of fuzzy sets and
fuzzy numbers in capturing opinion data when there
are uncertainties in those opinions, even from experts.
This paper has shown the applicability of the
approach in collecting important factors that will
drive greater usage and adoption of electric vehicles.
Through the application of the analytical methods
utilizing fuzzy inputs, it is seen that the top three
factors are battery recharge time followed by the cost
of the battery and positive impact towards the
environment. Energy efficiency was the fourth most
significant factor that was not very far behind the top
three (shown by the yellow dot in the star plot).
ACKNOWLEDGMENTS
I would like to thank my father for introducing me to
fuzzy numbers as a way of capturing opinions that
have inherent uncertainty. I also thank the six experts
who provided me their opinions in a timely manner.
Finally, I thank the reviewers who provided valuable
comments.
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